1. Technical Field
This invention generally relates to a vacuum cleaner floor tool, and more particularly to a vacuum cleaner floor tool for use with deep-pile carpet.
2. Background
In the prior art today there is no suitable vacuum cleaner floor tool for use with high-capacity vacuum cleaners to clean deep-pile carpets, except those vacuum cleaners which feature electrically powered rotating beater bars which are used to agitate and brush the carpet fibers to dislodge particles of dust and dirt found at the bottom of the carpet between the carpet webbing and the attached fibers. There is a reason for this. High capacity vacuum cleaners, particularly those used in industrial applications, for example, those used by janitorial services cleaning office buildings, often provide section heads enabling air flows of 100 cubic feet per minute and higher. In other words, they provide a lot of suction. The typical non-beater bar or stationary floor tool, is not suitable for use with these types of vacuum cleaners for deep pile carpets. The reason is that the high suction air flow rates draw the floor tool down into the deep pile to the extent that the raking bars found on the front and rear periphery of the tool pneumatically sealed off the floor tool, such that the floor tool is literally sucked into the carpet. In this condition they are difficult to push across the carpet.
This is one of the reasons why the electrically powered rotating beater bar designs have been so popular. With these prior art designs, the suction head for the vacuum pump is not applied directly to the pile of the carpet, but instead is positioned and held above the carpet by the chassis or frame of the beater bar. Often times these electrically powered beater bar tools are provided with wheels so that the suction head stays above the top of the carpet, with the brushes on the beater bar brushing through the carpet to dislodge and hopefully bring up the dirt and dust which are normally found at the bottom of the carpet pile next to the carpet mat to which the pile is attached.
The rotating brushes found on electrically powered rotating beater bar floor tools are also very hard on the carpet. Each time the brushes are forced through the carpet pile, they break bonds between the carpet pile and the carpet mat and break off and dislodge fibers of the carpet, which are then later sucked into the vacuum cleaner. While this may not be a significant factor in low-traffic residential uses, for example a formal living room in a residential home, it is significant in high-traffic commercial areas where carpets are vacuumed frequently, perhaps even daily.
The facts that conventional vacuum cleaner floor tools will be sucked into deep-pile carpet, thereby sealing off the vacuum and making them very difficult to push around, and the damage done to deep-pile carpets by rotating beater bar brushes, are primary reasons why deep-pile carpets are not found in high-traffic commercial use buildings. Deep-pile carpets have been, in the prior art, simply too difficult to keep clean with conventional vacuum cleaner floor tools, and wear out too quickly if beater bar vacuum cleaners are used regularly to clean them.
Accordingly, it is an object of the present invention to provide a vacuum cleaner floor tool of a type that does not utilize rotating beater bar brushes, but instead simply applies vacuum and mild agitation of the carpet pile to clean the carpet. It is a further object of this invention to provide a vacuum cleaner floor tool which is not drawn into the carpet, thereby forming a pneumatic seal and thereby increasing the force required to push it back and forth across the carpet.